Process and apparatus for producing chemical action in gases.



'C. S. BRADLEY. 1

PROCESS AND APPARATUS FOR PRODUCING CHEMICAL ACTION IN GASES.

APPLICATlON FILED MAY 1, 1909. RENEWED sEPT.2. 1914.

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7- z I 5 m C. S'. BRADLEY. PROCESS AND APPARATUS FOR PRODUCING CHEMICALACTION IN GASES. I

APPLICATION FILED MAY I, I909- RENEWED SEPT. 2, I914. 1,1 34,583.

Patented Apr. 6, 1915.

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PROCESS AND APPARATUS FOR PRODUCING CHEMICAL ACTION IN GASES.

APPLICATION FILED MAY 1. 19:09. RENEWED SEPT-2. ISM.

Patented Apr. 6, 1915 4 SHEETFBHBBT 3.

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C. S. BRADLEY PROCESS AND APPARATUS FOR PRODUCING CHEMICAL ACTION INGASES.

APPLICATION FILED MAY 1,. L909- RENEWED SEPT. 2, 1914.

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CHAILES S.' BRADLEY, OF NEW YORK, N. Y.

PROCESS AND APPARATUS FOR PROD UGING CHEMICAL ACTION IN GASES.

Application filed Kay 1, 1909, Serial No. 493,818.

ratus for causing said changes to take place in an elficient manner witha maximum yield of the product sought.

My invention may be explained by reference to processes which haveheretofore been disclosed for effecting chemical combination betweennitrogen and oxygen, or the synthetic production of nitrogen compoundsfrom the atmosphere, as, for example, in the patents granted to myselfand to D. R. Lovejoy, September 30, 1902, numbered 709,867; 709,868, andothers. In these and other published processes, the heat required forthe reaction was supplied in the form of electric arcs, and a feature ofthe patented processes referred to was the production of a thin orelongated are, because such an are presented a relatively large surfaceto the surrounding cooler gases and thus their cooling eflect wasutilized to the best advantage and dissociation of the products orreversion of the reaction was diminished. Other processes which havebeen published from time to time have sought in various ways to takeadvantage of the cooling of the products 'by the surrounding gases.

Further investigation of the .subject has led me to the discovery thatin the transition from the temperature of the arc to the lowertemperature surrounding the arc, dissociation-reversal of the reactionsoughtoccurred to a considerable extent, whereby the yield wasmaterially reduced. The reaction is for the most part confined to thecore of' the are where the reaction temperature is maintained, and theproducts there formed are dissociated to a considerable extent when theycome to the surrounding 'cooler arc envelop. As the temperature of theproducts falls gradually in passing. from the hot core outward tothecooler arc envelop not only are the products dissociated in considerableSpecification of Letters recent.

, Patented Apr. 6, 1915.

Renewed September 2, 1914. Serial No. 859,816.

proportion, but the gases suffer repeated combination and dissociation,involving waste of the energy in addition to the loss due todissociation. These losses in yield I and energy are the result of a tooslow reduction in temperature from the reaction temperature at the coreof the arc to the temperature at which tendency to dissociation ceasesand the products become fixed.

Chemical reactions, such as above referred to, involve the absorption ofheat energy, part of which is taken up in the chemical change produced,the excess appearing in the high temperature of the products; but inreturning to the ordinary conditions of temperature required forhandling and utilization of the products reversal of the reaction takesplace. By conversion of the excess heat energy into a chemically.inactive form of energy at a point before reversion of dissociation ofthe products takes place, or by eliminating the time interval betweenthe temperature of formation of the products and their return to,ordinary temperature, dissociation or reversion of the products isprevented and they become fixed. This I accomplish by converting theexcess heat energy into velocity by causing the products to expandsuddenly. The velocity will, as will be understood, have no chemicaleffeet on the products. The consequent sudden cooling results inbringing the products to a temperature at which they become fixed andmay be utilized and handled. These phenomenaapply not only to thefixation of atmospheric nitrogen as in the processes referred to, butalso to other reactions subject to reversibility or decomposition ofproducts by reason of heat conditions, as will appear in the following.

In further explanation of my invention, itmay be pointed out that insuch reactions there are what may be termed three temperature zones. Thezone of formation or reaction, the zone ofdissociation and the zone ofpermanence or fixation. WVhen the products are endothermic substances acertain amount of energy in the form of heat must be supplied beforereaction can take place. The zone of formation commences where reactionbegins and extends to where it is comthirdtemperature' zone or region inwhich the products formed in the reaction zone are isting in one zone toundergo the change in.

the other. From these considerations it fol lows that, if all theproducts formed by bringing the gases to the combining temperature, orfirst-named temperature zone, could be immediately carried to the thirdtemperature zone or zone of permanence, (overpassing the zone ofdissociation) there would be practically no loss from dissocia-' tion.And if, in addition to this, the whole volume or charge of the gases, asdistinguished from the small fraction thereof actually traversed by thearcs, as in known processes, were brought to the combining temperature,the maximum yield would be secured.

The object of my present invention is to provide both these conditions.

Although, in the foregoing, I have speclfically referred to theformation of the oxids of nitrogen, it is to be distinctly understoodthat this is by way of illustration only, and that my present inventionembraces the effecting of reaction in gases generally, includingdissociation of such as dissociate at elevated temperature and whosecomponents;

are stable or permanent at ordinary or lower temperatures, all as willappear in the following.-

For the better understanding of my invention and the practicalerformance of the same I haveillustrate in the accompanying drawing aform of apparatus suitable therefor in which Figure 1 illustrates in" apartly sectional view the reaction chamber and preheating chambers; Fig.2 is a partly sectional view of the apparatus from the reaction chamberto the duct leading to the recovery apparatus (not shown) Fig. 2 tailView of some of the parts shown in 2; Fig. 3 is a sectional view of adetail taken 'on line' "Fig. 2; Fig. 4 is a sectional view on enlargedscale of the end of the,

water pipe; Fig. 5 is a detail sectional view on enlarged scale showingthe expansion apparatu's ;'Fig.-" 6 is a sectional view of a modifiedform of electrode; and Fi 7 is a partly sectional view of a modified ormof apparatus.

. In Fig. 1, the reaction chamber is indicated by the numeral 1. Saidchamber may be conveniently formed of a hollow block 2 of suitable sizeand of refractory material. The chamber is, for the production ofnitrogen oxids, preferably lined with a material, such as thoria,capable of withstanding the high temperature and inert to the gases is asectional de- 7 forming with mouth piece 7 amazes treated. Said liningis indicated at 3, The ends of the chamber are closed by slabs or blocks4 through which enter the electrodes 55, which are connected to asuitable source of electrical energy (not shown). The discharge betweenthe electrodes furnishes the heat energy for the reaction. It is notnecessary to the invention that the heat be supplied in theform of theelectric arc. Any other suitable means of heating .the gases to thereaction temperature, such,

for example, as Heating the Walls of the chamber, may be employed, butas the electric arc affords a convenient and direct means of heating itwill. be found preferable in practice. The gases to be acted upon areadmitted to the chamber, in the apparatus illustrated, from belowthrough the inlet 6 and the products are discharged therefrom throughthe expansion outlet 7. The gases maybe admitted directly to thereaction chamber but it isadvantageous to preheat them. Accordingly Ihave shown preheaters 8, 8, interposed in the path of the gases on theirWay to the reaction chamber. These preheaters are. shown of theregenerator type. A furnace 9 supplies the heat, the heated combustionproducts from which may, by means of valve 10, be directed to eitherpreheater alternately. As will bereadily understood; one preheater isbeingheated by the furnace while the other is imparting its heat toaction chamber. Valves 11, 11 control the discharge of the producm ofcombustion from the preheaters and the admission of the heated gasestherefrom to the reaction chamber.

From the reaction chamber 1 the products are suddenly expanded into achamber or space 13 (Fig. '5) of low pressure, the obexpansion of theproducts and a consequent sudden and immediate cooling thereof from thetemperature of the reaction chamber to a temperature below that at whichsaid products would tend to dissociate. Rarefaction or maintenance ofreduced pressure in the space 13., is obtained, in theapparatus'illustrated, by an expansion nozzle formed by outlet 7 and ane ector or propelling device or mouth 7". This expansion nozzle isformed by a mouth piece 7 which may be of metal, tapered internally andforming (as shown) a continuation of the outlet 7. Surrounding the endof this nozzle is a collar a tapered annular mouth 7". In the collar 7is a duct 7 communicating with the mouth 7 and to this duct is connecteda pipe 7 for leading in steam or other fluid under pressure. The parts7, 7, 7", 7, 7", and 7 form the ejector or expansion nozzle. By means ofthe steam or other fluid delivered under pressure throughpipe 7 andissuing from mouth 7" gases going to the reect being to cause a suddenor immediate let 6.

rarefaction is produced in space 13 in the vicinity of the mouth ofnozzle 7; The steam also serves to absorb some ofthe heat from theproducts. In cases where the products would be in uriously ordisadvantageously affected by steam, another fluid will be substitutedtherefor; also, 1f desired, any other suitable means for producing therequired rarefactlon may be substituted forthe nozzle 7 D such, forexample, as a vacuum pump or other rarefaction apparatus. Suchmodifications are to be regarded as within the scope of the invention.

The parts constituting the expansion nozzle may be secured on thereaction chamber by means of a plate 21 in which are screwthreaded mouthpiece/7 and collar 7. Plate 21 is secured in place by means of tie bolts22 which pass therethrough and through a plate 23 at the bottom of thechamber. The union of the inlet pipes 26 from the preheaters, passesthrough this plate 23 to 1n- The trunk or pipe 14 into which the produtsfrom the reaction chamber and expansion nozzle discharge is threaded incollar 7, as shown. Beyond the portion of said pipe whi h constitutesthe rarefaction chamber 13 is arranged an adjustable compresslon nozzleindicated at 14. This nozzle is formed by means of an adjustable taperedvalve 28, the stem 28 of which passes through a stuffing box 29 in thewall of the pipe 14. By adjustment of the valve 28 the size of thenozzle 14 and the degree of compression exerted on the products isregulated. In the vicinity of this compression nozzle is arranged awater jet to absorb the heat due to compression. This jet is provided bymeans of a pipe 20 passing through stufling box 27 and axially throughvalve 28. At its end pipe 20'is provided with a tip 20 provided withupwardly inclined discharging passages 20"; and the tip is pointed ortapered as at 20 in order to present'little or no obstruction to theflow of the products. To compensate for the space occupied by pipe 20the trunk 14 is enlarged, as shown, in the vicinity of said pipe. Beyondvalve 28 the trunk 14 is enlarged and passes to the absorption devices.These devices form no part of my invention and hence are not shown. Theymay consist of absorption towers of well known construction, or otherabsorption or recovery devices, depending upon the. nature of theproducts obtained and the form in which it is desired to absorb orcollect them. Provision may also be made for mixing other gases orsubstances with the products, as

.for example, by supplying oxygen to convert the lower oxids of nitrogen(where these form the products) into the higher oxids: but thesubsequent treatment of the products after their fixation in accordancewith my invention *is immaterial so far as the present invention isconcerned.

In several of the views of the drawings I have illustrated modificationsof parts of the apparatus. In Fig. 6 I have shown a metallic'electrode,which may be of iron or copper, having its interior hollow or chamberedfor the circulation of cooling water. The use of such electrodes isadvantageous in preventing dilution or contamination of the gases orproducts" by carbon dioxid which might occur in the use of carbonelectrodes.

In Fig. 7 is another modification in which a cooler 30 of tubularconstruction is shown interposed between the expansion nozzle and theoutlet of the reaction chamber for the purpose of preventing a rise oftemperature due to friction or recompression and at the same time thedensity of the issuing products is increased and their volume lessened.This permits the steam delivered to pipe 7 or the pump, as the case maybe, to be more efiective.

Where nitrogen compounds are to be produced according'to my. invention,air or a suitable mixture of oxygen and nitrogen is led through thepreheaters to the reaction chamber. The preheaters are workedalternately. As shown in Fig. 1 of the drawings, the preheater on theleft is being heated by the furnace; and the preheater on the right isgiving up its heat to the gases or air entering at the inlet 25 andpassing through branch pipe 26 to the inlet 6 of the reaction chamber.The gases entering the chamber in the preheated condition have theirelectrical conductivity increased thereby, and the arcs willconsequently have greater length so that adjustment of the electrodesfor striking or maintaining the arc will be unnecessary. It isunderstood, however, that the electrodes may be adjusted toward and fromeach other by any well known means as shown. Where carbon electrodes areused, the preheating of the gases enables penetration of the electrodesinto thechamber unnecessary, so that the carbon dioxid formed near thetips may pass off without entering the chamber. The electrodes areconnected with a suitable source of current which may be eitheralternating or direct, supplying constant current.

The gases in the chamber are heated to the reaction or combiningtemperature,

somewhat above that temperature. For the production of nitrogencompounds the temperature will be in the neighborhood of 3,000-3,500 C.In order to insure the requisite velocity of discharge from the chamberthe gases may be supplied to the chamber under pressure. From thereaction chamber the products issue through the expanison nozzle intothe space 13 of reduced pressure. Assuming that the velocity of flow ofthe products from the reaction cham ber to the expansion chamber bethree thousand five hundred to four thousand feet per second and thelength of the expansion open ing or nozzle be three inches, the time ofexpansion would occupy about one fifteenbe in the neighborhood of 1500degrees C.'

The particular temperature after expansion is not of vital importance solong as it is below the temperature at which the gaseous compoundsformed tend to dissociate. The difference in pressure of the gasesbetween that in the reaction chamber and that in the expansion chamberfor the above conditions will be in the neighborhood of the ratio of15': l.33. The cooling being thus instantaneous, the products areobtained 'with practically no loss and the yield is obviously greatlyincreased over the processes heretofore known; The eflect of theexpansion nozzle is to convert the energy of temperature andpressure inthe reaction chamber into velocit The velocity will of course have no inuence upon the chemical product formed. The steam delivered through pipe7 should have a velocity somewhat in excess of that of the productsissuing through the nozzle so as to have a carrying effect upon thesame. A steam pressure of 100 to 150 pounds will, in the instance given,be suitable. Where the velocity of the products is such that a highsteam pressure is required to have a carrying effect, the employment ofa cooling device, as in Fig. 7, in advance of-thesteam nozzle permitsthe use of lower steam pressure.

Leaving therarefaction chamber, the velocity of the products is checkedor con verted into pressure. This is accomplished by adjustablecompression nozzle and valve 28. The heat incident to the compression isabsorbed by the water jets from water nozzle 20, the point of theirapplication being adjusted by raising or lowering the pipe 20.

' From the compression nozzle the products pass to the horizontallyarranged portion 14 of pipe 14; to the absorption apparatus. It will beunderstood that the compression nozzle and pipe 20 will be adjusted toobtain the proper relations between the rate of flow of the'products,the temperature and the rate of expansion.

From'the foregoing it will be seen that, as distinguished from knownprocesses in which a slow cooling of the productsby heat lnterchangewith the surrounding volume of gases, and the consequent slow transit ofthe products through what I have termed the.

zone of dissociation, my invention produces in immediate orinstantaneous coolingbywhich the products are carried at once from thereaction zone or zone of combination to the zone of permanence-thetransit of the products through the zone of dissociation being-soinstantaneous that, for practical consideration, it may be said that thedissociation zone is passed over and the products go im ing used, but anatmosphere of hydrogen is supplied to the reaction chamber which, underthe influence of the arcs, combines with the carbon of the electrodes,or with the carbon with which the interior of the chamber may be lined,to produce the acetylene. Or, hydrocarbon ases may be supplied to thechamber and the action of the heat from the arcs will cause a portion ofthe carbon and hydro en contained therein to unite to form acety ene.

The invention may also be employed upon exothermic substances as forexample. by dissociating combined gases or compounds into theirconstituents and maintaining the dissociated condition by theinstantaneous.

lowering of the temperature through the temperature zone in whichrecomblnation would take place. For instance, .it is well known thatsteam is decomposed at a temperature in the neighborhood of 2,000 0.;

but owing to the impracticability of separating the hydrogen and theoxygen produced in the zone of dissociation, recombination or ignitiontakes place, water be ing formed as the products cool. By my invention,ignition or recombination is prevented by the instantaneous loweringofthe temperature of the products by sudden expansion and cooling beyondthe temperature zone in which recombination takes place. In treatingthis class of bodies the same principles apply. The re-' action isreversible but reversion is prevented by bringin the temperaturesuddenly to the zone 0 fixation or permanence. The zones will in thesecases 'have different names. The highest zone in the scale is the zoneof dissociation (reaction); the inter mediate zone is the zone ofrecombination, and the lowest zone is, as before, the zone of permanenceor fixation.

It will be apparent from the foregoing that the electric arcs arementioned as only one formof obtaining the necessary reactiontemperature for causing the chemical reactions to be produced. Any othersuitable form of heat may be substituted, such as in candescent bodiesover which the gases may be passed; or the walls of the reaction chambermay be heated up in any convenient and suitable manner to obtain thenecessary temperature of reaction. If desired, the pressure in thereaction chamber may be increased by supplying the gases to be com binedunder pressure.

While Ihave referred to gaseous bodies as entering into combination toform new products, it' will be obvious that substances may be combinedwhich are not gases, but

which under the conditions of the reaction form gaseous compounds orproduc s, as in the case of the production of acetylene above mentioned.1

While I have described the application of my invention to the severalinstances above mentioned, it is to be understood that I refer to suchinstances by way of illustration and that my invention is not limited toany specific embodiment thereof but includes broadly carryingof theproductslformed under the conditions of reaction instantaneously throughwhat I have termed the zone of decomposition (or recombination) bycausing a sudden expansion or reduction of pressure with the consequentdrop in tem-' perature below the critical point where the product formedwould tend to decompose or revert to its constituents, or vice versa.

Having described my invention, what I claim is:

1. The process of fixing the products of endo-thermic reactions, ingases, which consists in heating avolume of the gas to reactiontemperature, immediately dischargingor removing the products from thearea or zone of reaction and simultaneously expanding said products andimparting velocity thereto and thereby rapidly removing said productsfrom the area or zone of reaction and reducin the temperature thereofbelow that at which they would tend to dissociate or revert to theircomponents.

2. The process of eifectin chemical changes in gases which consists inbringing the gases to reaction temperature and immediately impartingvelocity to the product and discharging the same into an area of reducedpressure to cause an immediate fall in temperature below that at whichthe product formed by the reaction would tend to reverse.

3. The process of efiecting chemical changes in gases, which consists incontinuinclosed chamber,

the temperature of said products below that at which dissociationthereof tends to occur.

it. The process for producing oxids of nitrogen, which consists incharging a mixture of oxygen and nitrogen gases into an heating saidcharge throughout to the combining temperature, immediately impartingvelocity to and discharging the products from said chamber in an area ofreduced pressure, whereby the temperature of the products is reducedbelow that at which dissociation tends to occur.

5. The process of producing oxids of nitrogen, which consists inintroducing a mixture of nitrogen and oxygen into an inclosed chamber,striking electric arcs in said chamber, imparting velocity to theproduct to suddenly discharge the same into an area of reduced pressureto reduce the temperature of said product to a point where the prod notformed is fixed or permanent.

6. The process of forming nitrogen oxids which consist in heating amixture of nitrogen and oxygen to the reaction temperature, immediatelydischarging or removing the products from the area or zone of reactionand simultaneously expanding said' prodnets. and imparting velocitythereto and thereby rapidly removing said products from the area or zoneof reaction and reducing the temperature thereof below that at whichthey would tend to dissociate or revert to their components.

7. The process of producing nitrogen oxids, which consists in heating amixture of nitrogen and oxygen to the reaction temperature, suddenlyexpanding the products formed, recompressing said products and absorbingthe heat due to recompression.

8. An apparatus for the purpose described, having in combination areaction chamber, means to introduce gases thereto, means for heatingthe gases in said chamber, an expansion outlet for discharging andexpanding the products formed in said chamber, and means to impartvelocity to the products through said outlet.

9. An apparatus for the purpose de scribed, having in combination areaction chamber, means tointroduce gases thereto, means for heating thegases in said chamber, a rarefaction chamber, an expansion outletleading from the reaction chamber to the rarefaction chamber, andexhaust means for impartin' velocity to the discharging gases connecteto said reaction chamber.

10. In apparatus for the purpose described, the combination of areaction chamv sorb the heat due .to'

' the preheating chamber,

ber,-means to introduce gases thereto,means for heating the gases insaid chamber, a trunk leading from said chamber, exhaustion meansconnected to. said trunk for exhausting and rarefying the products fromsaid chamber, means in said trunk for recompressing said products andmeans to abrecompression.

11. In apparatus for the purpose described, the combination of areaction chamber, means to introduce gases to-said chame ber, means toheat the gases in said chamber,

an expansion nozzle connected to said chamber, means for exhausting theproduct from said chamber through said nozzle, an adjustable compressionnozzle in the path of the products from the expansion nozzle and meansto absorb the heat due to compression.

12. In apparatus of the I character described, the combination of apreheating chamber, a reaction chamber connected to means. to heat thegases in the reaction chamber to the reaction temperature, an expansionnozzle and a compression nozzle connectedto the reaction chamber andsuccessively arranged in the path of the products from said chamber, anexhaust apparatus for exhausting the .products from the reaction chamberthrough said nozzles and means to absorb the heat due to compression inthe compression nozzle.

ber,

ejector nozzle in said trunk, means. to discharge fluidunder pressurefrom said nozzle to eject or discharge theproducts from the chamberthrough the expanding outlet, a compression nozzleiin the path of theproducts from said outlet, and means to dis-- chargea cooling fluid inthe compression nozzle.

14. In apparatus for the purpose described, the combination of areaction chamber, means to introduce gases to said chammeans to heat thegases in said chamber, an expansion nozzle connected to said chamber,means to absorb heat from the products on their Way to the expansionnozzle, means for exhausting the product from said chamber through saidnozzle, an adjustable compression nozzle in the path of the productsfrom the expansion nozzle and means to absorb the heat due tocompression.

vicinity ofsaid CHARLE$ S. BRA ljLEY Witnesses:

LAURA E.- MONK,

lIAnRY KNIGHT.

